Table 1.

Demographic characteristics for neuroblastoma patients and cancer-free controls (Anhui and combined subjects)

Variables	Anhui province					Combined subjects
	Cases (N=119)		Controls (N=264)		Pa	Cases (N=512)		Controls (N=1076)		Pa
	No.	%	No.	%		No.	%	No.	%
Age range, month	0.001-108		0.001-96		0.507	0-132		0.001-156		0.937
Mean ± SD	26.86 ± 23.19		29.67 ± 27.52			33.82 ± 26.96		33.70 ± 28.68
≤18	52	43.70	125	47.35		178	34.77	430	39.96
>18	67	56.30	139	52.65		334	65.23	646	60.04
Gender
Female	50	42.02	112	42.42	0.941	218	42.58	454	42.02	0.885
Male	69	57.98	152	57.58		294	57.42	622	57.98
Clinical stages
I	45	37.82				114	22.31
II	52	43.70				145	28.38
III	14	11.76				82	16.05
IV	8	6.72				151	29.55
4s	0	0.00				11	2.15
NA	0	0.00				8	1.57
Sites of origin
Adrenal gland	43	36.13				196	38.28
Retroperitoneal region	41	34.45				128	25.00
Mediastinum	26	21.85				135	26.37
Other region	9	7.56				45	8.79
NA	0	0.00				8	1.56

SD, standard deviation, NA, not available. ^a Two-sided χ² test for distributions between neuroblastoma patients and controls.